Magnetic field detection apparatus and current detection apparatus

ABSTRACT

A magnetic field detection apparatus includes a magnetoresistive effect element and a helical coil. The magnetoresistive effect element includes a magnetoresistive effect film extending in a first axis direction. The helical coil includes a parallel connection including first and second parts extending in a second axis direction inclined with respect to the first axis direction. The first and second parts are adjacent to each other in a third axis direction and coupled to each other in parallel. The helical coil is wound around the magnetoresistive effect element while extending along the third axis direction. The magnetoresistive effect film overlaps the first and second parts in a fourth axis direction orthogonal to the second and third axis directions. The helical coil is configured to be supplied with a current and thereby configured to generate an induction magnetic field to be applied to the magnetoresistive effect film in the third axis direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority PatentApplication Nos. 2019-224095 filed on Dec. 11, 2019 and 2020-030861filed on Feb. 26, 2020, the entire contents of each of which areincorporated herein by reference.

BACKGROUND

The disclosure relates to a magnetic field detection apparatus and acurrent detection apparatus each of which includes a magnetoresistiveeffect element.

Some magnetic field detection apparatuses using magnetoresistive effectelements have been proposed. For example, Japanese Unexamined PatentApplication Publication No. 2016-001118 discloses a magnetic fielddetection apparatus including a magnetoresistive effect element and aconductor, in which a centerline of the conductor along the direction ofa current flow and a centerline of the magnetoresistive effect elementalong the direction of its length are oriented in different directionsfrom each other.

SUMMARY

A first magnetic field detection apparatus according to one embodimentof the disclosure includes a magnetoresistive effect element and ahelical coil. The magnetoresistive effect element includes amagnetoresistive effect film extending in a first axis direction. Thehelical coil includes a parallel connection including a first part and asecond part that each extend in a second axis direction inclined withrespect to the first axis direction and that are adjacent to each otherin a third axis direction and coupled to each other in parallel, thethird axis direction being different from both of the first axisdirection and the second axis direction. The helical coil is woundaround the magnetoresistive effect element while extending along thethird axis direction. The magnetoresistive effect film overlaps both ofthe first part and the second part in a fourth axis direction orthogonalto both of the second axis direction and the third axis direction. Thehelical coil is configured to be supplied with a current and therebyconfigured to generate an induction magnetic field to be applied to themagnetoresistive effect film in the third axis direction.

A second magnetic field detection apparatus according to one embodimentof the disclosure includes a first magnetoresistive effect element, asecond magnetoresistive effect element, and a helical coil. The firstmagnetoresistive effect element includes a first magnetoresistive effectfilm extending in a first axis direction. The second magnetoresistiveeffect element includes a second magnetoresistive effect film extendingin the first axis direction. The helical coil includes a first parallelconnection and a second parallel connection. The first parallelconnection includes a first part and a second part that each extend in asecond axis direction inclined with respect to the first axis directionand that are adjacent to each other in a third axis direction andcoupled to each other in parallel, the third axis direction beingdifferent from both of the first axis direction and the second axisdirection. The second parallel connection includes a third part and afourth part that each extend in the second axis direction and that areadjacent to each other in the third axis direction and coupled to eachother in parallel. The helical coil is wound around the firstmagnetoresistive effect element and the second magnetoresistive effectelement while extending along the third axis direction. The firstmagnetoresistive effect film overlaps both of the first part and thesecond part in a fourth axis direction orthogonal to both of the secondaxis direction and the third axis direction. The second magnetoresistiveeffect film overlaps both of the third part and the fourth part in thefourth axis direction. The helical coil is configured to be suppliedwith a current and thereby configured to generate an induction magneticfield to be applied to the first and second magnetoresistive effectfilms in the third axis direction.

A current detection apparatus according to one embodiment of thedisclosure includes a magnetoresistive effect element, a helical coil,and a conductor. The magnetoresistive effect element includes amagnetoresistive effect film extending in a first axis direction. Thehelical coil includes a parallel connection including a first part and asecond part each extending in a second axis direction inclined withrespect to the first axis direction. The first part and the second partare adjacent to each other in a third axis direction and coupled to eachother in parallel, the third axis direction being different from both ofthe first axis direction and the second axis direction. The helical coilis wound around the magnetoresistive effect element while extendingalong the third axis direction. The helical coil is configured to besupplied with a first current and thereby configured to generate a firstinduction magnetic field to be applied to the magnetoresistive effectfilm in the third axis direction. The conductor is configured to besupplied with a second current and thereby configured to generate asecond induction magnetic field to be applied to the magnetoresistiveeffect element in the third axis direction. The magnetoresistive effectfilm overlaps both of the first part and the second part in a fourthaxis direction orthogonal to both of the second axis direction and thethird axis direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the technology and are incorporated in and constitute apart of this specification. The drawings illustrate example embodimentsand, together with the specification, serve to explain the principles ofthe technology.

FIG. 1 is a schematic planar diagram illustrating an overallconfiguration example of a current detection apparatus according to oneexample embodiment of the disclosure.

FIG. 2A is a perspective diagram illustrating an overall configurationexample of a first current detection unit illustrated in FIG. 1.

FIG. 2B is a perspective diagram illustrating an overall configurationexample of a second current detection unit illustrated in FIG. 1.

FIG. 3A is a planar diagram for explaining a detailed configuration of afirst magnetoresistive effect element formed in a first elementformation region illustrated in FIG. 2A.

FIG. 3B is an explanatory diagram illustrating a setting operation inthe first current detection unit illustrated in FIG. 2A.

FIG. 3C is an explanatory diagram illustrating a resetting operation inthe first current detection unit illustrated in FIG. 2A.

FIG. 3D is a first schematic cross-sectional diagram illustrating acurrent detection operation in the first current detection unitillustrated in FIG. 2A.

FIG. 3E is a second schematic cross-sectional diagram illustrating thecurrent detection operation in the first current detection unitillustrated in FIG. 2A.

FIG. 3F is an explanatory diagram illustrating intensity distributionsof a setting magnetic field and a resetting magnetic field to be appliedto a first magnetoresistive effect film illustrated in FIG. 3A.

FIG. 3G is a planar diagram for explaining a detailed configuration of afourth magnetoresistive effect element formed in a fourth elementformation region illustrated in FIG. 2A.

FIG. 4A is a planar diagram for explaining a detailed configuration of athird magnetoresistive effect element formed in a third elementformation region illustrated in FIG. 2B.

FIG. 4B is a schematic cross-sectional diagram illustrating the settingoperation in the second current detection unit illustrated in FIG. 2B.

FIG. 4C is a schematic cross-sectional diagram illustrating theresetting operation in the second current detection unit illustrated inFIG. 2B.

FIG. 4D is a first schematic cross-sectional diagram illustrating thecurrent detection operation in the second current detection unitillustrated in FIG. 2B.

FIG. 4E is a second schematic cross-sectional diagram illustrating thecurrent detection operation in the second current detection unitillustrated in FIG. 2B.

FIG. 4F is a planar diagram for explaining a detailed configuration of asecond magnetoresistive effect element formed in a second elementformation region illustrated in FIG. 2B.

FIG. 5A is a first enlarged schematic perspective view of a portion of ahelical coil.

FIG. 5B is a second enlarged schematic perspective view of the portionof the helical coil.

FIG. 6A is an exploded perspective diagram illustrating a stackedstructure of the first magnetoresistive effect film illustrated in FIG.3A.

FIG. 6B is an exploded perspective diagram illustrating a stackedstructure of a second magnetoresistive effect film illustrated in FIG.4C.

FIG. 6C is an exploded perspective diagram illustrating a stackedstructure of a third magnetoresistive effect film illustrated in FIG.4B.

FIG. 6D is an exploded perspective diagram illustrating a stackedstructure of a fourth magnetoresistive effect film illustrated in FIG.4A.

FIG. 7 is a circuit diagram of the current detection apparatusillustrated in FIG. 1.

FIG. 8 is a first enlarged schematic perspective view of a portion of ahelical coil according to one modification example.

FIG. 9 is a second enlarged schematic perspective view of the portion ofthe helical coil according to the modification example.

FIG. 10A is a schematic planar diagram illustrating an overallconfiguration example of a magnetic field detection apparatus accordingto one example embodiment of the disclosure.

FIG. 10B is a circuit diagram of the magnetic field detection apparatusillustrated in FIG. 10A.

FIG. 11A is a planar diagram for explaining a detailed configuration ofa first element formation region illustrated in FIG. 10A.

FIG. 11B is a cross-sectional diagram for explaining the detailedconfiguration of the first element formation region illustrated in FIG.10A.

FIG. 12 is a planar diagram for explaining a detailed configuration of asecond element formation region illustrated in FIG. 10A.

FIG. 13 is a planar diagram for explaining a detailed configuration of athird element formation region illustrated in FIG. 10A.

FIG. 14 is a planar diagram for explaining a detailed configuration of afourth element formation region illustrated in FIG. 10A.

DETAILED DESCRIPTION

It is demanded that magnetic field detection apparatuses usingmagnetoresistive effect elements be high in detection sensitivity whilebeing small in size.

It is desirable to provide a magnetic field detection apparatus and acurrent detection apparatus that achieve both of improved detectionsensitivity and size reduction.

In the following, some example embodiments and modification examples ofthe technology are described in detail with reference to theaccompanying drawings. Note that the following description is directedto illustrative examples of the technology and not to be construed aslimiting the technology. Factors including, without limitation,numerical values, shapes, materials, components, positions of thecomponents, and how the components are coupled to each other areillustrative only and not to be construed as limiting the technology.Further, elements in the following example embodiments which are notrecited in a most-generic independent claim of the disclosure areoptional and may be provided on an as-needed basis. The drawings areschematic and are not intended to be drawn to scale. Like elements aredenoted with the same reference numerals to avoid redundantdescriptions. Note that the description is given in the following order.

1. Example Embodiment (an example of a current detection apparatus thatdetects a current flowing through a bus and includes a bridge circuitand a helical coil, the bridge circuit including four magnetoresistiveeffect elements, the helical coil having a winding direction thatreverses at an intermediate point along the coil)

2. Modification Examples 1. Example Embodiment [Configuration of CurrentDetection Apparatus 100]

First, a configuration of a current detection apparatus 100 according toan example embodiment of the disclosure will be described with referenceto FIGS. 1 to 7.

FIG. 1 is a schematic planar diagram illustrating an overallconfiguration example of the current detection apparatus 100. Asillustrated in FIG. 1, the current detection apparatus 100 may include acurrent line (a bus) 5 to be supplied with a signal current Im (Im1,Im2) to be detected, and a substrate 1 provided with current detectionunits 10A and 10B. The current detection unit 10A may include amagnetoresistive effect element 11 formed in an element formation regionX1, a magnetoresistive effect element 14 formed in an element formationregion X4, and a coil part 6A. The current detection unit 10B mayinclude a magnetoresistive effect element 13 formed in an elementformation region X3, a magnetoresistive effect element 12 formed in anelement formation region X2, and a coil part 6B. The coil part 6A mayinclude an upper wiring line 6UA1 and an upper wiring line 6UA2 coupledto each other in series. The upper wiring line 6UA1 may include, forexample, four upper wiring line patterns 61UA1 to 64UA1 coupled to eachother in parallel. The upper wiring line 6UA2 may include, for example,four upper wiring line patterns 61UA2 to 64UA2 coupled to each other inparallel. Note that FIG. 1 illustrates an example in which the coil part6A includes two upper wiring lines (the upper wiring line 6UA1 and theupper wiring line 6UA2); however, the coil part 6A may include only asingle upper wiring line or three or more upper wiring lines. The coilpart 6B may include an upper wiring line 6UB1 and an upper wiring line6UB2 coupled to each other in series. The upper wiring line 6UB1 mayinclude, for example, four upper wiring line patterns 61UB1 to 64UB1coupled to each other in parallel. The upper wiring line 6UB2 mayinclude, for example, four upper wiring line patterns 61UB2 to 64UB2coupled to each other in parallel. Note that FIG. 1 illustrates anexample in which the coil part 6B includes two upper wiring lines (theupper wiring line 6UB1 and the upper wiring line 6UB2); however, thecoil part 6B may include only a single upper wiring line or three ormore upper wiring lines. Further, the coil part 6A and the coil part 6Bmay be coupled to each other in series to form a single helical coil 6.The helical coil 6 may be configured to be supplied with a feedbackcurrent If (If1, If2), a setting current Is, and a resetting current Ir,all of which will be described in detail later. Note that the feedbackcurrent If, the setting current Is, and the resetting current Ir may besupplied to the helical coil 6 at mutually different timings.

The magnetoresistive effect elements 11 to 14 in the present exampleembodiment may each correspond to a specific but non-limiting example ofa “magnetoresistive effect element” according to one embodiment of thedisclosure. Each of the magnetoresistive effect elements 11 and 14 mayalso correspond to a specific but non-limiting example of a “firstmagnetoresistive effect element” according to one embodiment of thedisclosure, and each of the magnetoresistive effect elements 12 and 13may also correspond to a specific but non-limiting example of a “secondmagnetoresistive effect element” according to one embodiment of thedisclosure. Further, the helical coil 6 may correspond to a specific butnon-limiting example of a “helical coil” according to one embodiment ofthe disclosure. The bus 5 may correspond to a specific but non-limitingexample of a “conductor” according to one embodiment of the disclosure.

[Current Detection Unit 10A]

FIG. 2A is an enlarged perspective view of a half portion of the currentdetection unit 10A illustrated in FIG. 1, that is, a region where theupper wiring line 6UA1 or the upper wiring line 6UA2 is provided. Theregion where the upper wiring line 6UA1 is provided and the region wherethe upper wiring line 6UA2 is provided may have substantially the sameconfiguration. Thus, a description here will be given without making adistinction between the two, and a term “upper wiring line 6UA” will beused to collectively refer to the upper wiring lines 6UA1 and 6UA2. Asillustrated in FIG. 2A, the current detection unit 10A may have astructure in which, for example, a lower wiring line 6LA, the substrate1 including the magnetoresistive effect element 11 and themagnetoresistive effect element 14 arranged side by side in a Y-axisdirection, and the upper wiring line 6UA are stacked in this order in aZ-axis direction above the bus 5. The upper wiring line 6UA and thelower wiring line 6LA may constitute a portion of the coil part 6A andmay be coupled to each other in series. FIG. 2A illustrates an examplein which the lower wiring line 6LA includes eight lower wiring linepatterns 61LA to 68LA, and the upper wiring line 6UA includes four upperwiring line patterns 61UA to 64UA. The eight lower wiring line patterns61LA to 68LA of the lower wiring line 6LA may be adjacent to each otherin an X-axis direction and coupled to each other in parallel. The fourupper wiring line patterns 61UA to 64UA of the upper wiring line 6UA maybe adjacent to each other in the X-axis direction and coupled to eachother in parallel. In an embodiment of the disclosure, however, thenumber of the lower wiring line patterns of the lower wiring line 6LAand the number of the upper wiring line patterns of the upper wiringline 6UA are not limited to these numbers and may be set to any numbers.The eight lower wiring line patterns 61LA to 68LA may be coupled to asingle power supply in parallel. The four upper wiring line patterns61UA to 64UA may also be coupled to the power supply in parallel toconstitute the upper wiring line 6UA serving as a parallel connection.

As described above, the upper wiring line 6UA and the lower wiring line6LA may be coupled to each other in series. Therefore, for example, in acase where a setting current Is in a +Y direction flows through theupper wiring line 6UA (the upper wiring line patterns 61UA to 64UA), asetting current Is in a −Y direction may flow through the lower wiringline 6LA (the lower wiring line patterns 61LA to 68LA). In a case wherea resetting current Ir in the −Y direction flows through the upperwiring line 6UA, a resetting current Ir in the +Y direction may flowthrough the lower wiring line 6LA. Further, in a case where a signalcurrent Im1 in the +Y direction flows through the bus 5, a feedbackcurrent If1 in the +Y direction may flow through the upper wiring line6UA, and a feedback current If1 in the −Y direction may flow through thelower wiring line 6LA. Further, in a case where a signal current Im2 inthe −Y direction flows through the bus 5, a feedback current If2 in the−Y direction may flow through the upper wiring line 6UA, and a feedbackcurrent If2 in the +Y direction may flow through the lower wiring line6LA. Note that a reference sign If1 in FIG. 1 indicates the direction ofthe feedback current flowing through the upper wiring line 6UA and thelower wiring line 6LA. In FIG. 2A, an arrow with a reference sign JS11indicates a direction of a magnetization JS11 of a magnetization pinnedlayer S11 (described later) of a magnetoresistive effect film MR1(described later) included in the magnetoresistive effect element 11,and an arrow with a reference sign JS41 indicates a direction of amagnetization JS41 of a magnetization pinned layer S41 (described later)of a magnetoresistive effect film MR4 (described later) included in themagnetoresistive effect element 14.

The upper wiring line patterns 61UA to 64UA and the lower wiring linepatterns 61LA to 68LA may all extend in the Y-axis direction. The upperwiring line patterns 61UA to 64UA may be disposed opposite to the lowerwiring line patterns 61LA to 68LA, with the magnetoresistive effectelements 11 and 14 being interposed between the upper wiring linepatterns 61UA to 64UA and the lower wiring line patterns 61LA to 68LA inthe Z-axis direction.

Here, for example, the upper wiring line pattern 61UA may correspond toa specific but non-limiting example of a “first part” according to oneembodiment of the disclosure, and the upper wiring line pattern 62UA maycorrespond to a specific but non-limiting example of a “second part”according to one embodiment of the disclosure. Further, the lower wiringline patterns 61LA and 62LA may each correspond to a specific butnon-limiting example of a “third part” according to one embodiment ofthe disclosure, and the lower wiring line patterns 63LA and 64LA mayeach correspond to a specific but non-limiting example of a “fourthpart” according to one embodiment of the disclosure.

[Current Detection Unit 10B]

FIG. 2B is an enlarged perspective view of a half portion of the currentdetection unit 10B illustrated in FIG. 1, that is, a region where theupper wiring line 6UB1 or the upper wiring line 6UB2 is provided. Theregion where the upper wiring line 6UB1 is provided and the region wherethe upper wiring line 6UB2 is provided may have substantially the sameconfiguration. Thus, a description here will be given without making adistinction between the two, and a term “upper wiring line 6UB” will beused to collectively refer to the upper wiring lines 6UB1 and 6UB2. Asillustrated in FIG. 2B, the current detection unit 10B may have astructure in which, for example, a lower wiring line 6LB, the substrate1 including the magnetoresistive effect element 13 and themagnetoresistive effect element 12 arranged side by side in the Y-axisdirection, and the upper wiring line 6UB are stacked in this order inthe Z-axis direction above the bus 5. Note that the bus 5 and thesubstrate 1 may be common between the current detection unit 10A and thecurrent detection unit 10B. The upper wiring line 6UB and the lowerwiring line 6LB may constitute a portion of the coil part 6B and may becoupled to each other in series. FIG. 2B illustrates an example in whichthe lower wiring line 6LB includes eight lower wiring line patterns 61LBto 68LB, and the upper wiring line 6UB includes four upper wiring linepatterns 61UB to 64UB. The eight lower wiring line patterns 61LB to 68LBof the lower wiring line 6LB may be adjacent to each other in the X-axisdirection and coupled to each other in parallel. The four upper wiringline patterns 61UB to 64UB of the upper wiring line 6UB may be adjacentto each other in the X-axis direction and coupled to each other inparallel. In an embodiment of the disclosure, however, the number of thelower wiring line patterns of the lower wiring line 6LB and the numberof the upper wiring line patterns of the upper wiring line 6UB are notlimited to these numbers and may be set to any numbers. The eight lowerwiring line patterns 61LB to 68LB may be coupled to the foregoing powersupply in parallel. The four upper wiring line patterns 61UB to 64UB mayalso be coupled to the power supply in parallel to constitute the upperwiring line 6UB serving as a parallel connection. In FIG. 2B, an arrowwith a reference sign JS31 indicates a direction of a magnetization JS31of a magnetization pinned layer S31 (described later) of amagnetoresistive effect film MR3 (described later) included in themagnetoresistive effect element 13, and an arrow with a reference signJS21 indicates a direction of a magnetization JS21 of a magnetizationpinned layer S21 (described later) of a magnetoresistive effect film MR2(described later) included in the magnetoresistive effect element 12.

Because the coil part 6A and the coil part 6B may be coupled to eachother in series, a setting current Is and a resetting current Irsupplied from the power supply common between the coil part 6A and thecoil part 6B may flow through the coil part 6B. In the current detectionunit 10B, however, the setting current Is and the resetting current Irmay flow in directions opposite to those in the current detection unit10A. In a specific but non-limiting example, in a case where a settingcurrent Is in the +Y direction flows through the upper wiring line 6UAof the current detection unit 10A, a setting current Is in the −Ydirection may flow through the upper wiring line 6UB of the currentdetection unit 10B. In this case, a setting current Is in the +Ydirection may flow through the lower wiring line 6LB (the eight lowerwiring line patterns 61LB to 68LB). In a case where a resetting currentIr in the +Y direction flows through the upper wiring line 6UB (theupper wiring line patterns 61UB to 64UB), a resetting current Ir in the−Y direction may flow through the lower wiring line 6LB (the eight lowerwiring line patterns 61LB to 68LB). Further, in a case where a signalcurrent Im1 in the +Y direction flows through the bus 5, a feedbackcurrent If1 in the +Y direction may flow through the upper wiring line6UB, and a feedback current If1 in the −Y direction may flow through thelower wiring line 6LB. Further, in a case where a signal current Im2 inthe −Y direction flows through the bus 5, a feedback current If2 in the−Y direction may flow through the upper wiring line 6UB, and a feedbackcurrent If2 in the +Y direction may flow through the lower wiring line6LB. Note that the reference sign If1 in FIG. 1 indicates the directionof the feedback current flowing through the upper wiring line 6UB andthe lower wiring line 6LB.

The upper wiring line patterns 61UB to 64UB and the lower wiring linepatterns 61LB to 68LB may all extend in the Y-axis direction. The lowerwiring line patterns 61LB to 68LB may be disposed opposite to the upperwiring line patterns 61UB to 64UB, with the magnetoresistive effectelements 13 and 12 being interposed between the lower wiring linepatterns 61LB to 68LB and the upper wiring line patterns 61UB to 64UB inthe Z-axis direction.

Here, for example, the upper wiring line pattern 61UB may correspond toa specific but non-limiting example of the “first part” according to oneembodiment of the disclosure, and the upper wiring line pattern 62UB maycorrespond to a specific but non-limiting example of the “second part”according to one embodiment of the disclosure. Further, the lower wiringline patterns 61LB and 62LB may each correspond to a specific butnon-limiting example of the “third part” according to one embodiment ofthe disclosure, and the lower wiring line patterns 63LB and 64LB mayeach correspond to a specific but non-limiting example of the “fourthpart” according to one embodiment of the disclosure.

[Magnetoresistive Effect Element 11]

FIG. 3A is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect element 11 formed in the element formationregion X1 of the current detection unit 10A. Further, FIGS. 3B to 3E arecross-sectional diagrams each illustrating a portion of the currentdetection unit 10A. Note that FIG. 3A illustrates a plurality ofmagnetoresistive effect films MR1 constituting the magnetoresistiveeffect element 11 and the upper wiring line patterns 61UA to 63UA out ofthe upper wiring line patterns 61UA to 64UA disposed above themagnetoresistive effect films MR1, and omits other components.

As illustrated in FIG. 3A, the magnetoresistive effect element 11 mayinclude a plurality of magnetoresistive effect films MR1 arranged in amatrix to align in the X-axis direction and the Y-axis direction. Notethat FIG. 3A illustrates a total of eight magnetoresistive effect filmsMR1 in a four-by-two arrangement (i.e., four in the Y-axis direction andtwo in the X-axis direction) by way of example; however, the number ofthe magnetoresistive effect films MR1 is not specifically limited. Theplurality of magnetoresistive effect films MR1 may be coupled to eachother in series, and each extend in a W-axis direction that is inclinedwith respect to both of the X-axis direction and the Y-axis direction.Thus, each of the plurality of magnetoresistive effect films MR1 mayhave a shape anisotropy in the W-axis direction. An angle θ1 formedbetween the W-axis direction and the Y-axis direction may be 45°, forexample. Each of the plurality of magnetoresistive effect films MR1 mayinclude a first end part 11A, a second end part 11B, and an intermediatepart 11C between the first end part 11A and the second end part 11B. Thefirst end part 11A and the second end part 11B may be portions thatrespectively include a first end 11AT and a second end 11BT of themagnetoresistive effect film MR1 that are opposite to each other in theW-axis direction. Further, in FIG. 3A, an arrow with a reference signJS13 indicates a direction of a magnetization JS13 of a magnetizationfree layer S13 (described later) in an initial state in eachmagnetoresistive effect film MR1. In a specific but non-limitingexample, the direction of the magnetization JS13 of the magnetizationfree layer S13 in the initial state may be substantially parallel to theW-axis direction. Further, an arrow with the reference sign JS11 in FIG.3A indicates the direction of the magnetization JS11 of themagnetization pinned layer S11 (described later) in eachmagnetoresistive effect film MR1. In a specific but non-limitingexample, the direction of the magnetization JS11 may be substantiallyparallel to a V-axis direction orthogonal to the W-axis direction. Themagnetoresistive effect films MR1 may thus have sensitivity in theV-axis direction.

Here, the W-axis direction may correspond to a specific but non-limitingexample of a “first axis direction” according to one embodiment of thedisclosure. The Y-axis direction may correspond to a specific butnon-limiting example of a “second axis direction” according to oneembodiment of the disclosure. The X-axis direction may correspond to aspecific but non-limiting example of a “third axis direction” accordingto one embodiment of the disclosure. The Z-axis direction may correspondto a specific but non-limiting example of a “fourth axis direction”according to one embodiment of the disclosure.

As illustrated in FIG. 3A, in a plan view in the Z-axis direction,multiple ones of the plurality of magnetoresistive effect films MR1 thatare arranged in the Y-axis direction to constitute a line Y11 may eachbridge between the upper wiring line pattern 61UA and the upper wiringline pattern 62UA each extending in the Y-axis direction, for example.In a specific but non-limiting example, the upper wiring line pattern61UA and the upper wiring line pattern 62UA of the helical coil 6 mayrespectively overlap, in the Z-axis direction, the first end part 11Aand the second end part 11B of each of the magnetoresistive effect filmsMR1 that constitute the line Y11. Likewise, in a plan view in the Z-axisdirection, multiple ones of the plurality of magnetoresistive effectfilms MR1 that constitute a line Y12 adjacent to the line Y11 may eachbridge between the upper wiring line pattern 62UA and the upper wiringline pattern 63UA each extending in the Y-axis direction. In a specificbut non-limiting example, the upper wiring line pattern 62UA and theupper wiring line pattern 63UA of the helical coil 6 may respectivelyoverlap, in the Z-axis direction, the first end part 11A and the secondend part 11B of each of the magnetoresistive effect films MR1 thatconstitute the line Y12. Further, although not illustrated in FIG. 3A,multiple ones of the plurality of magnetoresistive effect films MR1 thatconstitute a line (a line Y13 illustrated in FIG. 3B described later)that is adjacent to the line Y12 and located on a side of the line Y12opposite to the line Y11 may each bridge between the upper wiring linepattern 63UA and the upper wiring line pattern 64UA in a plan view inthe Z-axis direction. In a specific but non-limiting example, the upperwiring line pattern 63UA and the upper wiring line pattern 64UA of thehelical coil 6 may respectively overlap, in the Z-axis direction, thefirst end part 11A and the second end part 11B of each of themagnetoresistive effect films MR1 that constitute the line Y13. In someembodiments, the upper wiring line patterns 61UA to 63UA may overlap thefirst end 11AT in the first end part 11A in the Z-axis direction, andthe upper wiring line patterns 62UA to 64UA may overlap the second end11BT in the second end part 11B in the Z-axis direction.

Further, as illustrated in FIGS. 3B and 3C, the lower wiring linepattern 62LA of the helical coil 6 may overlap, in the Z-axis direction,the first end part 11A of each of the magnetoresistive effect films MR1that constitute the line Y11, and the lower wiring line pattern 63LA mayoverlap, in the Z-axis direction, the second end part 11B of each of themagnetoresistive effect films MR1 that constitute the line Y11.Likewise, the lower wiring line pattern 64LA may overlap, in the Z-axisdirection, the first end part 11A of each of the magnetoresistive effectfilms MR1 that constitute the line Y12, and the lower wiring linepattern 65LA may overlap, in the Z-axis direction, the second end part11B of each of the magnetoresistive effect films MR1 that constitute theline Y12. Further, the lower wiring line pattern 66LA may overlap, inthe Z-axis direction, the first end part 11A of each of themagnetoresistive effect films MR1 that constitute the line Y13, and thelower wiring line pattern 67LA may overlap, in the Z-axis direction, thesecond end part 11B of each of the magnetoresistive effect films MR1that constitute the line Y13. It is to be noted that FIGS. 3B and 3C areschematic diagrams illustrating positional relationships between theupper wiring line 6UA, the lower wiring line 6LA, and themagnetoresistive effect films MR1 in the Z-axis direction (thicknessdirection).

As illustrated in FIGS. 3A and 3B, supplying the helical coil 6 with asetting current Is may cause a setting magnetic field SF− in a −Xdirection to be applied to each of the magnetoresistive effect filmsMR1. As illustrated in FIG. 3C, supplying the helical coil 6 with aresetting current Ir may cause a resetting magnetic field RF+ in a +Xdirection to be applied to each of the magnetoresistive effect filmsMR1. Further, as illustrated in FIG. 3D, in a case where a signalcurrent Im1 in the +Y direction flows through the bus 5, a signalmagnetic field Hm1 in the +X direction may be applied to each of themagnetoresistive effect films MR1. In this case, supplying the helicalcoil 6 with a feedback current If1 may cause a feedback magnetic fieldHf1 in the −X direction to be applied to each of the magnetoresistiveeffect films MR1 to cancel out the signal magnetic field Hm1. Further,as illustrated in FIG. 3E, in a case where a signal current Im2 in the−Y direction flows through the bus 5, a signal magnetic field Hm2 in the−X direction may be applied to each of the magnetoresistive effect filmsMR1. In this case, supplying the helical coil 6 with a feedback currentIf2 may cause a feedback magnetic field Hf2 in the +X direction to beapplied to each of the magnetoresistive effect films MR1 to cancel outthe signal magnetic field Hm2.

It is to be noted that the setting magnetic field SF (SF+, SF−) and theresetting magnetic field RF (RF+, RF−) may correspond to a specific butnon-limiting example of an “induction magnetic field” or a “firstinduction magnetic field” according to one embodiment of the disclosure.

As illustrated in FIG. 3F, intensities (absolute values) of the settingmagnetic field SF and the resetting magnetic field RF to be applied toeach of the first end part 11A and the second end part 11B may be higherthan intensities (absolute values) of the setting magnetic field SF andthe resetting magnetic field RF to be applied to the intermediate part11C. One reason for this is that the first end part 11A and the secondend part 11B may overlap the upper wiring line pattern 61UA and theupper wiring line pattern 62UA in the Z-axis direction whereas no upperwiring line patterns or no lower wiring line patterns may overlap theintermediate part 11C in the Z-axis direction; in other words, theintermediate part 11C may be disposed farther from the upper wiring linepatterns 61UA and 62UA and the lower wiring line patterns 61LA to 68LAof the helical coil 6, compared with the first end part 11A and thesecond end part 11B. Note that FIG. 3F is an explanatory diagramillustrating the intensity distribution in the X-axis direction of thesetting magnetic field SF and the resetting magnetic field RF to beapplied to the magnetoresistive effect films MR1. In FIG. 3F, thehorizontal axis represents position (arbitrary units) in the X-axisdirection, and the vertical axis represents the magnetic field intensity(arbitrary units).

[Magnetoresistive Effect Element 14]

FIG. 3G is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect element 14 formed in the element formationregion X4 of the current detection unit 10A. Note that FIG. 3Gillustrates a plurality of magnetoresistive effect films MR4constituting the magnetoresistive effect element 14 and the upper wiringline patterns 61UA to 63UA out of the upper wiring line patterns 61UA to64UA disposed above the magnetoresistive effect films MR4, and omitsother components.

As illustrated in FIG. 3G, the magnetoresistive effect element 14 mayinclude a plurality of magnetoresistive effect films MR4 arranged in amatrix to align in the X-axis direction and the Y-axis direction. Notethat FIG. 3G illustrates a total of eight magnetoresistive effect filmsMR4 in a four-by-two arrangement (i.e., four in the Y-axis direction andtwo in the X-axis direction) by way of example; however, the number ofthe magnetoresistive effect films MR4 is not specifically limited. Theplurality of magnetoresistive effect films MR4 may be coupled to eachother in series, and each extend in the W-axis direction that isinclined with respect to both of the X-axis direction and the Y-axisdirection. Thus, each of the plurality of magnetoresistive effect filmsMR4 may have a shape anisotropy in the W-axis direction. Each of theplurality of magnetoresistive effect films MR4 may include a first endpart 14A, a second end part 14B, and an intermediate part 14C betweenthe first end part 14A and the second end part 14B. Note that the firstend part 14A and the second end part 14B may be portions thatrespectively include a first end 14AT and a second end 14BT of themagnetoresistive effect film MR4 that are opposite to each other in theW-axis direction. Further, in FIG. 3G, an arrow with a reference signJS43 indicates a direction of a magnetization JS43 of a magnetizationfree layer S43 (described later) in an initial state in eachmagnetoresistive effect film MR4. The direction of the magnetizationJS43 of the magnetization free layer S43 in the initial state may besubstantially parallel to the W-axis direction. Further, an arrow withthe reference sign JS41 in FIG. 3G indicates the direction of themagnetization JS41 of the magnetization pinned layer S41 (describedlater) in each magnetoresistive effect film MR4. The direction of themagnetization JS41 may be substantially parallel to the V-axis directionorthogonal to the W-axis direction. The magnetoresistive effect filmsMR4 may thus have sensitivity in the V-axis direction.

As illustrated in FIG. 3G, in a plan view in the Z-axis direction,multiple ones of the plurality of magnetoresistive effect films MR4 thatare arranged in the Y-axis direction to constitute a line Y41 may eachbridge between the upper wiring line pattern 61UA and the upper wiringline pattern 62UA, for example. In a specific but non-limiting example,the upper wiring line pattern 61UA and the upper wiring line pattern62UA may respectively overlap, in the Z-axis direction, the first endpart 14A and the second end part 14B of each of the magnetoresistiveeffect films MR4 that constitute the line Y41. Likewise, in a plan viewin the Z-axis direction, multiple ones of the plurality ofmagnetoresistive effect films MR4 that constitute a line Y42 may eachbridge between the upper wiring line pattern 62UA and the upper wiringline pattern 63UA. In a specific but non-limiting example, the upperwiring line pattern 62UA and the upper wiring line pattern 63UA mayrespectively overlap, in the Z-axis direction, the first end part 14Aand the second end part 14B of each of the magnetoresistive effect filmsMR4 that constitute the line Y42. Further, although not illustrated inFIG. 3G, multiple ones of the plurality of magnetoresistive effect filmsMR4 that constitute a line (which will be referred to as a line Y43 forconvenience of explanation) adjacent to the line Y42 and located on aside of the line Y42 opposite to the line Y41 may each bridge betweenthe upper wiring line pattern 63UA and the upper wiring line pattern64UA in a plan view in the Z-axis direction. In a specific butnon-limiting example, the upper wiring line pattern 63UA and the upperwiring line pattern 64UA may respectively overlap, in the Z-axisdirection, the first end part 14A and the second end part 14B of each ofthe magnetoresistive effect films MR4 that constitute the line Y43. Insome embodiments, the upper wiring line patterns 61UA to 63UA mayoverlap the first end 14AT in the first end part 14A in the Z-axisdirection, and the upper wiring line patterns 62UA to 64UA may overlapthe second end 14BT in the second end part 14B in the Z-axis direction.

Further, the lower wiring line pattern 62LA of the helical coil 6 mayoverlap, in the Z-axis direction, the first end part 14A of each of themagnetoresistive effect films MR4 that constitute the line Y41, and thelower wiring line pattern 63LA may overlap, in the Z-axis direction, thesecond end part 14B of each of the magnetoresistive effect films MR4that constitute the line Y41. Likewise, the lower wiring line pattern64LA may overlap, in the Z-axis direction, the first end part 14A ofeach of the magnetoresistive effect films MR4 that constitute the lineY42, and the lower wiring line pattern 65LA may overlap, in the Z-axisdirection, the second end part 14B of each of the magnetoresistiveeffect films MR4 that constitute the line Y42. Further, the lower wiringline pattern 66LA may overlap, in the Z-axis direction, the first endpart 14A of each of the magnetoresistive effect films MR4 thatconstitute the line Y43, and the lower wiring line pattern 67LA mayoverlap, in the Z-axis direction, the second end part 14B of each of themagnetoresistive effect films MR4 that constitute the line Y43.

In the magnetoresistive effect element 14, as in the magnetoresistiveeffect element 11, supplying the helical coil 6 with the setting currentIs may cause the setting magnetic field SF− in the −X direction to beapplied to each of the magnetoresistive effect films MR4. Further,supplying the helical coil 6 with the resetting current Ir may cause theresetting magnetic field RF+ in the +X direction to be applied to eachof the magnetoresistive effect films MR4.

[Magnetoresistive Effect Element 13]

FIG. 4A is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect element 13 formed in the element formationregion X3 of the current detection unit 10B. Further, FIGS. 4B to 4E arecross-sectional diagrams each illustrating a portion of the currentdetection unit 10B. Note that FIG. 4A illustrates a plurality ofmagnetoresistive effect films MR3 constituting the magnetoresistiveeffect element 13 and the upper wiring line patterns 61UB to 63UB out ofthe upper wiring line patterns 61UB to 64UB disposed above themagnetoresistive effect films MR3, and omits other components.

As illustrated in FIG. 4A, the magnetoresistive effect element 13 mayinclude a plurality of magnetoresistive effect films MR3 arranged in amatrix to align in the X-axis direction and the Y-axis direction. Notethat FIG. 4A illustrates a total of eight magnetoresistive effect filmsMR3 in a four-by-two arrangement (i.e., four in the Y-axis direction andtwo in the X-axis direction) by way of example; however, the number ofthe magnetoresistive effect films MR3 is not specifically limited. Theplurality of magnetoresistive effect films MR3 may be coupled to eachother in series, and each extend in the W-axis direction inclined withrespect to both of the X-axis direction and the Y-axis direction. Thus,each of the plurality of magnetoresistive effect films MR3 may have ashape anisotropy in the W-axis direction. Each of the plurality ofmagnetoresistive effect films MR3 may include a first end part 13A, asecond end part 13B, and an intermediate part 13C between the first endpart 13A and the second end part 13B. Note that the first end part 13Aand the second end part 13B may be portions that respectively include afirst end 13AT and a second end 13BT of the magnetoresistive effect filmMR3 that are opposite to each other in the W-axis direction. Further, inFIG. 4A, an arrow with a reference sign JS33 indicates a direction of amagnetization JS33 of a magnetization free layer S33 (described later)in an initial state in each magnetoresistive effect film MR3. Thedirection of the magnetization JS33 of the magnetization free layer S33in the initial state may be substantially parallel to the W-axisdirection. Further, an arrow with the reference sign JS31 in FIG. 4Aindicates the direction of the magnetization JS31 of the magnetizationpinned layer S31 (described later) in each magnetoresistive effect filmMR3. The direction of the magnetization JS31 may be substantiallyparallel to the V-axis direction orthogonal to the W-axis direction. Themagnetoresistive effect films MR3 may thus have sensitivity in theV-axis direction.

As illustrated in FIG. 4A, in a plan view in the Z-axis direction,multiple ones of the plurality of magnetoresistive effect films MR3 thatare arranged in the Y-axis direction to constitute a line Y31 may eachbridge between the upper wiring line pattern 61UB and the upper wiringline pattern 62UB, for example. In a specific but non-limiting example,the upper wiring line pattern 61UB and the upper wiring line pattern62UB may respectively overlap, in the Z-axis direction, the first endpart 13A and the second end part 13B of each of the magnetoresistiveeffect films MR3 that constitute the line Y31. Likewise, multiple onesof the plurality of magnetoresistive effect films MR3 that constitute aline Y32 may each bridge between the upper wiring line pattern 62UB andthe upper wiring line pattern 63UB in a plan view in the Z-axisdirection. In a specific but non-limiting example, the upper wiring linepattern 62UB and the upper wiring line pattern 63UB may respectivelyoverlap, in the Z-axis direction, the first end part 13A and the secondend part 13B of each of the magnetoresistive effect films MR3 thatconstitute the line Y32. Further, although not illustrated in FIG. 4A,multiple ones of the plurality of magnetoresistive effect films MR3 thatconstitute a line (which will be referred to as a line Y33 forconvenience of explanation) adjacent to the line Y32 and located on aside of the line Y32 opposite to the line Y31 may each bridge betweenthe upper wiring line pattern 63UB and the upper wiring line pattern64UB in a plan view in the Z-axis direction. In a specific butnon-limiting example, the upper wiring line pattern 63UB and the upperwiring line pattern 64UB may respectively overlap, in the Z-axisdirection, the first end part 13A and the second end part 13B of each ofthe magnetoresistive effect films MR3 that constitute the line Y33. Insome embodiments, the upper wiring line patterns 61UB to 63UB mayoverlap the first end 13AT in the first end part 13A in the Z-axisdirection, and the upper wiring line patterns 62UB to 64UB may overlapthe second end 13BT in the second end part 13B in the Z-axis direction.

Further, as illustrated in FIGS. 4A to 4E, the lower wiring line pattern62LB of the helical coil 6 may overlap, in the Z-axis direction, thefirst end part 13A of each of the magnetoresistive effect films MR3 thatconstitute the line Y31, and the lower wiring line pattern 63LB mayoverlap, in the Z-axis direction, the second end part 13B of each of themagnetoresistive effect films MR3 that constitute the line Y31.Likewise, the lower wiring line pattern 64LB may overlap, in the Z-axisdirection, the first end part 13A of each of the magnetoresistive effectfilms MR3 that constitute the line Y32, and the lower wiring linepattern 65LB may overlap, in the Z-axis direction, the second end part13B of each of the magnetoresistive effect films MR3 that constitute theline Y32. Further, the lower wiring line pattern 66LB may overlap, inthe Z-axis direction, the first end part 13A of each of themagnetoresistive effect films MR3 that constitute the line Y33, and thelower wiring line pattern 67LB may overlap, in the Z-axis direction, thesecond end part 13B of each of the magnetoresistive effect films MR3that constitute the line Y33.

In the current detection unit 10B, as illustrated in FIGS. 4A and 4B,supplying the helical coil 6 with the setting current Is may cause thesetting magnetic field SF+ in the +X direction to be applied to each ofthe magnetoresistive effect films MR3. As illustrated in FIG. 4C,supplying the helical coil 6 with the resetting current Ir may cause theresetting magnetic field RF− in the −X direction to be applied to eachof the magnetoresistive effect films MR3. Further, as illustrated inFIG. 4D, in a case where the signal current Im1 in the +Y directionflows through the bus 5, the signal magnetic field Hm1 in the +Xdirection may be applied to each of the magnetoresistive effect filmsMR3. In this case, supplying the helical coil 6 with the feedbackcurrent If1 may cause the feedback magnetic field Hf1 in the −Xdirection to be applied to each of the magnetoresistive effect films MR3to cancel out the signal magnetic field Hm1. Further, as illustrated inFIG. 4E, in a case where the signal current Im2 in the −Y directionflows through the bus 5, the signal magnetic field Hm2 in the −Xdirection may be applied to each of the magnetoresistive effect filmsMR3. In this case, supplying the helical coil 6 with the feedbackcurrent If2 may cause the feedback magnetic field Hf2 in the +Xdirection to be applied to each of the magnetoresistive effect films MR3to cancel out the signal magnetic field Hm2.

[Magnetoresistive Effect Element 12]

FIG. 4F is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect element 12 formed in the element formationregion X2. Note that FIG. 4F illustrates a plurality of magnetoresistiveeffect films MR2 constituting the magnetoresistive effect element 12 andthe upper wiring line patterns 61UB to 63UB out of the upper wiring linepatterns 61UB to 64UB disposed above the magnetoresistive effect filmsMR2, and omits other components.

As illustrated in FIG. 4F, the magnetoresistive effect element 12 mayinclude a plurality of magnetoresistive effect films MR2 arranged in amatrix to align in the X-axis direction and the Y-axis direction. Notethat FIG. 4F illustrates a total of eight magnetoresistive effect filmsMR2 in a four-by-two arrangement (i.e., four in the Y-axis direction andtwo in the X-axis direction) by way of example; however, the number ofthe magnetoresistive effect films MR2 is not specifically limited. Theplurality of magnetoresistive effect films MR2 may be coupled to eachother in series, and each extend in the W-axis direction inclined withrespect to both of the X-axis direction and the Y-axis direction. Thus,each of the plurality of magnetoresistive effect films MR2 may have ashape anisotropy in the W-axis direction. Each of the plurality ofmagnetoresistive effect films MR2 may include a first end part 12A, asecond end part 12B, and an intermediate part 12C between the first endpart 12A and the second end part 12B. Note that the first end part 12Aand the second end part 12B may be portions that respectively include afirst end 12AT and a second end 12BT of the magnetoresistive effect filmMR2 that are opposite to each other in the W-axis direction. Further, inFIG. 4F, an arrow with a reference sign JS23 indicates a direction of amagnetization JS23 of a magnetization free layer S23 (described later)in an initial state in each magnetoresistive effect film MR2. Thedirection of the magnetization JS23 of the magnetization free layer S23in the initial state may be substantially parallel to the W-axisdirection. Further, an arrow with the reference sign JS21 in FIG. 4Findicates the direction of the magnetization JS21 of the magnetizationpinned layer S21 (described later) in each magnetoresistive effect filmMR2. The direction of the magnetization JS21 may be substantiallyparallel to the V-axis direction orthogonal to the W-axis direction. Themagnetoresistive effect films MR2 may thus have sensitivity in theV-axis direction.

As illustrated in FIG. 4F, in a plan view in the Z-axis direction,multiple ones of the plurality of magnetoresistive effect films MR2 thatare arranged in the Y-axis direction to constitute a line Y21 may eachbridge between the upper wiring line pattern 61UB and the upper wiringline pattern 62UB, for example. In a specific but non-limiting example,the upper wiring line pattern 61UB and the upper wiring line pattern62UB may respectively overlap, in the Z-axis direction, the first endpart 12A and the second end part 12B of each of the magnetoresistiveeffect films MR2 that constitute the line Y21. Likewise, in a plan viewin the Z-axis direction, multiple ones of the plurality ofmagnetoresistive effect films MR2 that constitute a line Y22 may eachbridge between the upper wiring line pattern 62UB and the upper wiringline pattern 63UB. In a specific but non-limiting example, the upperwiring line pattern 62UB and the upper wiring line pattern 63UB mayrespectively overlap, in the Z-axis direction, the first end part 12Aand the second end part 12B of each of the magnetoresistive effect filmsMR2 that constitute the line Y22. Further, although not illustrated inFIG. 4F, multiple ones of the plurality of magnetoresistive effect filmsMR2 that constitute a line (which will be referred to as a line Y23 forconvenience of explanation) adjacent to the line Y22 and located on aside of the line Y22 opposite to the line Y21 may each bridge betweenthe upper wiring line pattern 63UB and the upper wiring line pattern64UB in a plan view in the Z-axis direction. In a specific butnon-limiting example, the upper wiring line pattern 63UB and the upperwiring line pattern 64UB may respectively overlap, in the Z-axisdirection, the first end part 12A and the second end part 12B of each ofthe magnetoresistive effect films MR2 that constitute the line Y23. Insome embodiments, the upper wiring line patterns 61UB to 63UB mayoverlap the first end 12AT in the first end part 12A in the Z-axisdirection, and the upper wiring line patterns 62UB to 64UB may overlapthe second end 12BT in the second end part 12B in the Z-axis direction.

Further, the lower wiring line pattern 62LB of the helical coil 6 mayoverlap, in the Z-axis direction, the first end part 12A of each of themagnetoresistive effect films MR2 that constitute the line Y21, and thelower wiring line pattern 63LB may overlap, in the Z-axis direction, thesecond end part 12B of each of the magnetoresistive effect films MR2that constitute the line Y21. Likewise, the lower wiring line pattern64LB may overlap, in the Z-axis direction, the first end part 12A ofeach of the magnetoresistive effect films MR2 that constitute the lineY22, and the lower wiring line pattern 65LB may overlap, in the Z-axisdirection, the second end part 12B of each of the magnetoresistiveeffect films MR2 that constitute the line Y22. Further, the lower wiringline pattern 66LB may overlap, in the Z-axis direction, the first endpart 12A of each of the magnetoresistive effect films MR2 thatconstitute the line Y23, and the lower wiring line pattern 67LB mayoverlap, in the Z-axis direction, the second end part 12B of each of themagnetoresistive effect films MR2 that constitute the line Y23.

In the magnetoresistive effect element 12, as in the magnetoresistiveeffect element 13, supplying the helical coil 6 with the setting currentIs may cause the setting magnetic field SF+ in the +X direction to beapplied to each of the magnetoresistive effect films MR2. Further,supplying the helical coil 6 with the resetting current Ir may cause theresetting magnetic field RF− in the −X direction to be applied to eachof the magnetoresistive effect films MR2.

[Bus 5]

The bus 5 may be a conductor extending in, for example, the Y-axisdirection, and may be supplied with a signal current Im (Im1, Im2) to bedetected by the current detection apparatus 100. A constituent materialof the bus 5 may include a highly electrically conductive material suchas Cu (copper), for example. An alloy containing Fe (iron) or Ni(nickel), or stainless steel may also be used as a constituent materialof the bus 5. A signal current Im1 flowing through the inside of the bus5 in, for example, the +Y direction, may enable the bus 5 to generate asignal magnetic field around the bus 5. In this case, the generatedsignal magnetic field may be applied to the magnetoresistive effectelements 11 to 14 in the +X direction. A signal current Im2 flowingthrough the inside of the bus 5 in the −Y direction may generate asignal magnetic field to be applied to the magnetoresistive effectelements 11 to 14 in the −X direction.

[Helical Coil 6]

FIGS. 5A and 5B are enlarged schematic perspective views of a portion ofthe helical coil 6. As already described, the helical coil 6 may includethe coil part 6A and the coil part 6B. As illustrated in FIGS. 5A and5B, the coil part 6A may be wound around the magnetoresistive effectelements 11 and 14 in a first winding direction CD1 while extendingalong the X-axis direction, for example. The coil part 6B may be woundaround the magnetoresistive effect elements 13 and 12 in a secondwinding direction CD2 opposite to the first winding direction CD1 whileextending along the X-axis direction, for example. A first end of thecoil part 6A and a first end of the coil part 6A may be coupled to eachother via a coupling part 6J. A terminal T3 may be coupled to thecoupling part 6J. The terminal T3 may be a frame ground (FG), forexample. A terminal T1 may be coupled to a second end of the coil part6A, and a terminal T2 may be coupled to a second end of the coil part6B. It is to be noted that in FIGS. 5A and 5B, the four upper wiringline patterns 61UA1 to 64UA1 are simplified into a single upper wiringline 6UA1, the four upper wiring line patterns 61UA2 to 64UA2 aresimplified into a single upper wiring line 6UA2, the four upper wiringline patterns 61UB1 to 64UB1 are simplified into a single upper wiringline 6UB1, the four upper wiring line patterns 61UB2 to 64UB2 aresimplified into a single upper wiring line 6UB2, the eight lower wiringline patterns 61LA to 68LA are simplified into a single lower wiringline 6LA, and the eight lower wiring line patterns 61LB to 68LB aresimplified into a single lower wiring line 6LB.

The helical coil 6 may be a wiring line surrounding the magnetoresistiveeffect elements 11 to 14 while being electrically insulated from each ofthe magnetoresistive effect elements 11 to 14. A constituent material ofthe helical coil 6 may include, for example, a highly electricallyconductive material such as Cu (copper), as with the bus 5.

As illustrated in FIG. 5A, the helical coil 6 may be configured toreceive supply of the setting current Is and the resetting current Irbetween, for example, the terminal T1 and the terminal T2, from thepower supply. Note that arrows in FIG. 5A indicate the setting currentIs flowing from the terminal T2 to the terminal T1. The resettingcurrent Ir is to flow in the opposite direction to the directionindicated by the arrows in FIG. 5A, thus flowing from the terminal T1 tothe terminal T2.

As illustrated in FIG. 5B, the helical coil 6 may be configured toreceive supply of the feedback currents If1 and If2 between the terminalT1 and the terminal T3 and between the terminal T2 and the terminal T3from the power supply. Note that arrows in FIG. 5B indicate the feedbackcurrent If1 flowing from the terminal T3 to the terminal T1 and alsofrom the terminal T3 to the terminal T2. The feedback current If2 is toflow in the opposite directions to the directions indicated by thearrows in FIG. 5B, thus flowing from the terminal T1 to the terminal T3and also from the terminal T2 to the terminal T3.

[Magnetoresistive Effect Films MR1 to MR4]

The magnetoresistive effect films MR1 and MR3 may each have a resistancevalue that decreases upon application of a signal magnetic field in the+V direction and increases upon application of a signal magnetic fieldin the −V direction. The magnetoresistive effect films MR2 and MR4 mayeach have a resistance value that increases upon application of a signalmagnetic field in the +V direction and decreases upon application of asignal magnetic field in the −V direction.

FIG. 6A is an exploded perspective diagram illustrating a stackedstructure of the magnetoresistive effect film MR1. FIG. 6B is anexploded perspective diagram illustrating a stacked structure of themagnetoresistive effect film MR2. FIG. 6C is an exploded perspectivediagram illustrating a stacked structure of the magnetoresistive effectfilm MR3. FIG. 6D is an exploded perspective diagram illustrating astacked structure of the magnetoresistive effect film MR4.

As illustrated in FIGS. 6A to 6D, respectively, the magnetoresistiveeffect films MR1 to MR4 may each have a spin-valve structure including aplurality of stacked functional films including magnetic layers. In aspecific but non-limiting example, as illustrated in FIG. 6A, themagnetoresistive effect film MR1 may have a configuration in which themagnetization pinned layer S11, an intermediate layer S12, and themagnetization free layer S13 are stacked in order in the Z-axisdirection. The magnetization pinned layer S11 may have the magnetizationJS11 pinned in a +V direction. The intermediate layer S12 may be anonmagnetic body. The magnetization free layer S13 may have themagnetization JS13 that varies depending on magnetic flux density of thesignal magnetic field. Each of the magnetization pinned layer S11, theintermediate layer S12, and the magnetization free layer S13 may be athin film that extends in an X-Y plane. Accordingly, the orientation ofthe magnetization JS13 of the magnetization free layer S13 may berotatable in the X-Y plane.

As illustrated in FIG. 6B, the magnetoresistive effect film MR2 may havea configuration in which the magnetization pinned layer S21, anintermediate layer S22, and the magnetization free layer S23 are stackedin order in the Z-axis direction. The magnetization pinned layer S21 mayhave the magnetization JS21 pinned in a −V direction. The intermediatelayer S22 may be a nonmagnetic body. The magnetization free layer S23may have the magnetization JS23 that varies depending on magnetic fluxdensity of the signal magnetic field. Each of the magnetization pinnedlayer S21, the intermediate layer S22, and the magnetization free layerS23 may be a thin film that extends in the X-Y plane. Accordingly, theorientation of the magnetization JS23 of the magnetization free layerS23 may be rotatable in the X-Y plane.

As illustrated in FIG. 6C, the magnetoresistive effect film MR3 may havea configuration in which the magnetization pinned layer S31, anintermediate layer S32, and the magnetization free layer S33 are stackedin order in the Z-axis direction. The magnetization pinned layer S31 mayhave the magnetization JS31 pinned in the +V direction. The intermediatelayer S32 may be a nonmagnetic body. The magnetization free layer S33may have the magnetization JS33 that varies depending on magnetic fluxdensity of the signal magnetic field. Each of the magnetization pinnedlayer S31, the intermediate layer S32, and the magnetization free layerS33 may be a thin film that extends in the X-Y plane. Accordingly, theorientation of the magnetization JS33 of the magnetization free layerS33 may be rotatable in the X-Y plane.

As illustrated in FIG. 6D, the magnetoresistive effect film MR4 may havea configuration in which the magnetization pinned layer S41, anintermediate layer S42, and the magnetization free layer S43 are stackedin order in the Z-axis direction. The magnetization pinned layer S41 mayhave the magnetization JS41 pinned in the −V direction. The intermediatelayer S42 may be a nonmagnetic body. The magnetization free layer S43may have the magnetization JS43 that varies depending on magnetic fluxdensity of the signal magnetic field. Each of the magnetization pinnedlayer S41, the intermediate layer S42, and the magnetization free layerS43 may be a thin film that extends in the X-Y plane. Accordingly, theorientation of the magnetization JS43 of the magnetization free layerS43 may be rotatable in the X-Y plane.

As described above, the magnetization pinned layers S11 and S31 in themagnetoresistive effect films MR1 and MR3 may have their respectivemagnetizations JS11 and JS31 pinned in the +V direction, whereas themagnetization pinned layers S21 and S41 in the magnetoresistive effectfilms MR2 and MR4 may have their respective magnetizations JS21 and JS41pinned in the −V direction.

Note that in the magnetoresistive effect films MR1 to MR4, themagnetization pinned layers S11, S21, S31, and S41, the intermediatelayers S12, S22, S32, and S42, and the magnetization free layers S13,S23, S33, and S43 may each have a single-layer structure or amulti-layer structure including a plurality of layers.

The magnetization pinned layers S11, S21, S31, and S41 may each includea ferromagnetic material such as cobalt (Co), cobalt-iron alloy (CoFe),or cobalt-iron-boron alloy (CoFeB). Optionally, the magnetoresistiveeffect films MR1 to MR4 may be provided with respectiveantiferromagnetic layers (not illustrated) that are adjacent to themagnetization pinned layers S11, S21, S31, and S41 and located on theopposite side from the intermediate layers S12, S22, S32, and S42. Suchantiferromagnetic layers may each include an antiferromagnetic materialsuch as platinum-manganese alloy (PtMn) or iridium-manganese alloy(IrMn). In the magnetoresistive effect films MR1 to MR4, theantiferromagnetic layers may be in a state in which a spin magneticmoment in the +V direction and a spin magnetic moment in the −Vdirection cancel each other out completely, and may act to pin theorientations of the magnetizations JS11 and JS31 of the magnetizationpinned layers S11 and S31 adjacent to the antiferromagnetic layers tothe +V direction, or pin the orientations of the magnetizations JS21 andJS41 of the magnetization pinned layers S21 and S41 adjacent to theantiferromagnetic layers to the −V direction.

In a case where the spin-valve structure serves as a magnetic tunneljunction (MTJ) film, the intermediate layers S12, S22, S32, and S42 mayeach be a nonmagnetic tunnel barrier layer including, for example,magnesium oxide (MgO), and may each be thin enough to allow a tunnelcurrent based on quantum mechanics to pass therethrough. The tunnelbarrier layer including MgO may be obtainable by a process such assputtering using a target including MgO, oxidation treatment of a thinfilm of magnesium (Mg), or a reactive sputtering of magnesium in anoxygen atmosphere. Further, an oxide or a nitride of aluminum (Al),tantalum (Ta), or hafnium (Hf), as well as MgO, may also be used toconfigure the intermediate layers S12, S22, S32, and S42. Note that theintermediate layers S12, S22, S32, and S42 may each include a platinumgroup element such as ruthenium (Ru) or gold (Au), or a nonmagneticmetal such as copper (Cu). In such a case, the spin-valve structure mayserve as a giant magnetoresistive effect (GMR) film.

The magnetization free layers S13, S23, S33, and S43 may be softferromagnetic layers and include substantially the same materials. Themagnetization free layers S13, S23, S33, and S43 may include, forexample, cobalt-iron alloy (CoFe), nickel-iron alloy (NiFe), orcobalt-iron-boron alloy (CoFeB).

[Bridge Circuit 7]

The four magnetoresistive effect elements 11 to 14 may be bridged toform a bridge circuit 7, as illustrated in FIG. 7. The magnetoresistiveeffect elements 11 to 14 may each be configured to detect a change in asignal magnetic field Hm (Hm1, Hm2) to be detected. As described above,the magnetoresistive effect elements 11 and 13 may each have aresistance value that decreases upon application of the signal magneticfield Hm1 in the +V direction and increases upon application of thesignal magnetic field Hm2 in the −V direction. The magnetoresistiveeffect elements 12 and 14 may each have a resistance value thatincreases upon application of the signal magnetic field Hm1 in the +Vdirection and decreases upon application of the signal magnetic fieldHm2 in the −V direction. Accordingly, in response to a change in thesignal magnetic field Hm, the magnetoresistive effect elements 11 and 13and the magnetoresistive effect elements 12 and 14 may output respectivesignals that are different in phase by 180° from each other, forexample.

As illustrated in FIG. 7, the bridge circuit 7 may have a configurationin which the magnetoresistive effect elements 11 and 12 coupled inseries and the magnetoresistive effect elements 13 and 14 coupled inseries are coupled to each other in parallel. In a specific butnon-limiting example, in the bridge circuit 7, one end of themagnetoresistive effect element 11 and one end of the magnetoresistiveeffect element 12 may be coupled to each other at a node P1; one end ofthe magnetoresistive effect element 13 and one end of themagnetoresistive effect element 14 may be coupled to each other at anode P2; another end of the magnetoresistive effect element 11 andanother end of the magnetoresistive effect element 14 may be coupled toeach other at a node P3; and another end of the magnetoresistive effectelement 12 and another end of the magnetoresistive effect element 13 maybe coupled to each other at a node P4. Here, the node P3 may be coupledto a power supply Vcc, and the node P4 may be coupled to a groundterminal GND. The node P1 may be coupled to an output terminal Vout1,and the node P2 may be coupled to an output terminal Vout2. The outputterminal Vout1 and the output terminal Vout2 may each be coupled to aninput-side terminal of a difference detector 8, for example. Thedifference detector 8 may detect a potential difference between the nodeP1 and the node P2 (i.e., a difference between voltage drops occurringat the magnetoresistive effect element 11 and the magnetoresistiveeffect element 14) when a voltage is applied between the node P3 and thenode P4, and may output the detected potential difference to anarithmetic circuit 9 as a difference signal S.

In FIG. 7, arrows with reference signs JS11 and JS31 schematicallyindicate orientations of the magnetizations JS11 and JS31 of themagnetization pinned layers S11 and S31 in the magnetoresistive effectelements 11 and 13. Further, arrows with reference signs JS21 and JS41in FIG. 7 schematically indicate orientations of the magnetizations JS21and JS41 of the magnetization pinned layers S21 and S41 in themagnetoresistive effect elements 12 and 14. As illustrated in FIG. 7,the orientation of the magnetizations JS11 and JS31 and the orientationof the magnetizations JS21 and JS41 may be opposite to each other. Inother words, FIG. 7 illustrates that the resistance value of themagnetoresistive effect element 11 and the resistance value of themagnetoresistive effect element 13 may change (e.g., increase ordecrease) in the same direction in response to a change in the signalmagnetic field. FIG. 7 also illustrates that both the resistance valueof the magnetoresistive effect element 12 and the resistance value ofthe magnetoresistive effect element 14 may change (decrease or increase)in a direction opposite to the direction of the change in the resistancevalue of each of the magnetoresistive effect elements 11 and 13 inresponse to the change in the signal magnetic field.

A current I10 from the power supply Vcc may be divided into a current I1and a current I2 at the node P3. The current I1 or the current I2 may besupplied to each of the magnetoresistive effect elements 11 to 14constituting the bridge circuit 7. Signals e1 and e2 may be extractedfrom the nodes P1 and P2 of the bridge circuit 7, respectively. Thesignals e1 and e2 may flow into the difference detector 8.

[Operations and Workings of Current Detection Apparatus 100]

In the current detection apparatus 100 according to the present exampleembodiment, it is possible to detect changes in the signal magneticfields generated by the signal currents Im1 and Im2 flowing through thebus 5 by calculating a potential difference V0 at the arithmetic circuit9.

[Detecting Operation]

First, consider a state of the current detection apparatus 100 where nosignal magnetic field is applied. Here, respective resistance values ofthe magnetoresistive effect elements 11 to 14 when a current I10 ispassed through the bridge circuit 7 are denoted by r1 to r4. The currentI10 from the power supply Vcc may be divided into two currents, i.e.,the current I1 and the current I2 at the node P3. Thereafter, thecurrent I1 having passed through the magnetoresistive effect element 11and the magnetoresistive effect element 12 and the current I2 havingpassed through the magnetoresistive effect element 14 and themagnetoresistive effect element 13 may join into one at the node P4. Insuch a case, a potential difference V between the node P3 and the nodeP4 is represented as follows.

V=I1*r1+I1*r2=I2*r4+I2*r3=I1*(r1+r2)=I2*(r4+r3)  (1)

Further, a potential V1 at the node P1 and a potential V2 at the node P2are represented as follows.

V1=V−I1*r1

V2=V−I2*r4

Accordingly, the potential difference V0 between the node P1 and thenode P2 is as follows.

V0=V2−V1=(V−I2*r4)−(V−I1*r1)=I1*r1−I2*r4  (2)

Here, from the equation (1), the following equation holds.

V0=r1/(r1+r2)×V−r4/(r4+r3)×V={r1/(r1+r2)−r4/(r4+r3)}×V  (3)

For the bridge circuit 7, it is possible to determine an amount ofchange in resistance by measuring the potential difference V0 betweenthe node P2 and the node P1 represented by the above equation (3) uponapplication of the signal magnetic field. Suppose here that applicationof the signal magnetic field results in changes of respective resistancevalues R1 to R4 of the magnetoresistive effect elements 11 to 14 byamounts of changes ΔR1 to ΔR4, respectively. In other words, supposethat the respective resistance values R1 to R4 of the magnetoresistiveeffect elements 11 to 14 after application of the signal magnetic fieldare as follows.

R1=r1+ΔR1

R2=r2+ΔR2

R3=r3+ΔR3

R4=r4+ΔR4

In this case, from the equation (3), the potential difference V0 uponapplication of the signal magnetic field is as follows.

V0={(r1+ΔR1)/(r1+ΔR1+r2+ΔR2)−(r4+ΔR4)/(r4+ΔR4+r3+ΔR3)}×V   (4)

Because the current detection apparatus 100 may be configured to allowthe resistance values R1 and R3 of the magnetoresistive effect elements11 and 13 and the resistance values R2 and R4 of the magnetoresistiveeffect elements 12 and 14 to exhibit changes in opposite directions toeach other, the amount of change ΔR4 and the amount of change ΔR1 maycancel each other out, and also the amount of change ΔR3 and the amountof change ΔR2 may cancel each other out. In this case, if comparison ismade between before and after the application of the signal magneticfield, there is substantially no increase in denominators of respectiveterms of the equation (4). In contrast, an increase or a decreaseappears in numerators of the respective terms because the amount ofchange ΔR1 and the amount of change ΔR4 always have opposite signs.

Suppose that all of the magnetoresistive effect elements 11 to 14 haveexactly the same characteristics, i.e., suppose that r1=r2=r3=r4=R andthat ΔR1=−ΔR2=ΔR3=−ΔR4=ΔR. In such a case, the equation (4) is expressedas follows.

V0={(R+ΔR)/(2×R)−(R−ΔR)/(2×R)}×V=(ΔR/R)×V

In such a manner, it is possible to measure the magnitudes of signalmagnetic fields by using the magnetoresistive effect elements 11 to 14whose characteristic values such as ΔR/R are known, and this makes itpossible to estimate the magnitudes of the signal currents Im1 and Im2that generate the signal magnetic fields.

In some embodiments, the current detection apparatus 100 may include acontroller 70. The controller 70 may be a microcomputer, for example.The controller 70 may include a central processing unit (CPU) that isconfigured to execute a control program to carry out predeterminedcontrol processing. The controller 70 may be configured to sequentiallycontrol the magnitudes of the feedback currents If1 and If2 to generatefeedback magnetic fields Hf1 and Hf2 having intensities that cancel outthe signal magnetic fields generated by the signal currents Im1 and Im2flowing through the bus 5, in other words, to allow an output from thebridge circuit 7 to remain zero. In such a case, it is possible toassume the magnitudes of the feedback currents If1 and If2 to besubstantially equal to those of the signal currents Im1 and Im2 flowingthrough the bus 5.

[Setting and Resetting Operations]

For a current detection apparatus of this kind, magnetizations of themagnetization free layers in the magnetoresistive effect elements mayoptionally be once aligned in a predetermined direction beforeperforming an operation of detecting a signal magnetic field. One reasonfor this is that it serves to increase accuracy of the operation ofdetecting the signal magnetic field. In a specific but non-limitingexample, an external magnetic field having a known magnitude may beapplied alternately in a predetermined direction and in a directionopposite thereto. Such operations will be referred to as setting andresetting operations on the magnetization of a magnetization free layer.

In the current detection apparatus 100 of the present exampleembodiment, the setting operation may be carried out by supplying thehelical coil 6 with a setting current Is. Supplying the helical coil 6with the setting current Is causes each of a setting magnetic field SF−and a setting magnetic field SF+ to be generated around the helical coil6, as illustrated in FIGS. 3B and 4B, respectively. As a result, in thecurrent detection unit 10A, it is possible to apply the setting magneticfield SF− in the −X direction to the magnetoresistive effect films MR1and MR4 of the magnetoresistive effect elements 11 and 14. This causesthe magnetizations of the magnetization free layers S13 and S43 of themagnetoresistive effect films MR1 and MR4 to be oriented in the −Wdirection, thus carrying out the setting operation. In the currentdetection unit 10B, it is possible to apply the setting magnetic fieldSF+ in the +X direction to the magnetoresistive effect films MR2 and MR3of the magnetoresistive effect elements 12 and 13. This causes themagnetizations of the magnetization free layers S23 and S33 of themagnetoresistive effect films MR2 and MR3 to be oriented in the +Wdirection, thus carrying out the setting operation. Further, theresetting operation may be carried out by supplying the helical coil 6with a resetting current Ir. Supplying the helical coil 6 with theresetting current Ir causes each of a resetting magnetic field RF+ and aresetting magnetic field RF− to be generated around the helical coil 6,as illustrated in FIGS. 3C and 4C, respectively. As a result, in thecurrent detection unit 10A, it is possible to apply the resettingmagnetic field RF+ in the +X direction to the magnetoresistive effectfilms MR1 and MR4 of the magnetoresistive effect elements 11 and 14.This causes the magnetizations of the magnetization free layers S13 andS43 of the magnetoresistive effect films MR1 and MR4 to be oriented inthe +W direction, thus carrying out the resetting operation. In thecurrent detection unit 10B, it is possible to apply the resettingmagnetic field RF− in the −X direction to the magnetoresistive effectfilms MR2 and MR3 of the magnetoresistive effect elements 12 and 13.This causes the magnetizations of the magnetization free layers S23 andS33 of the magnetoresistive effect films MR2 and MR3 to be oriented inthe −W direction, thus carrying out the resetting operation.

[Example Effects of Current Detection Apparatus 100]

In some embodiments, the upper wiring line pattern 61UA and the upperwiring line pattern 62UA of the helical coil 6 may overlap the first endpart 11A and the second end part 11B, respectively, in the Z-axisdirection in the magnetoresistive effect element 11, for example. As aresult, the intensities (absolute values) of the setting magnetic fieldSF− and the resetting magnetic field RF+ to be applied to the first endpart 11A and the intensities (absolute values) of the setting magneticfield SF− and the resetting magnetic field RF+ to be applied to thesecond end part 11B may be higher than the intensities (absolute values)of the setting magnetic field SF− and the resetting magnetic field RF+to be applied to the intermediate part 11C. This enables the settingmagnetic field SF and the resetting magnetic field RF generated by thehelical coil 6 to be effectively applied to the first end part 11A andthe second end part 11B of the magnetoresistive effect film MR1. Thedirection of the magnetization JS13 of the magnetization free layer S13is thereby evenly and sufficiently set and reset throughout themagnetoresistive effect film MR1. Similar workings are also obtainablefor the magnetoresistive effect elements 12 to 14. Consequently,according to the current detection apparatus 100 of the present exampleembodiment, it is possible to achieve high accuracy of current detectioneven in a case where dimensions thereof are reduced.

Furthermore, in some embodiments, instead of using a conductor that iswide enough to overlap the whole of each magnetoresistive effect film,the helical coil 6 is provided that may overlap only respective portions(the first end parts 11A to 14A and the second end parts 11B to 14B) ofthe magnetoresistive effect films. This allows, for example, the upperwiring line patterns 61UA, 61UB, 62UA and 62UB to be small in width.This consequently allows a value of a current that is to be supplied tothe helical coil 6 in order to obtain the predetermined setting magneticfields SF and resetting magnetic fields RF and the predeterminedfeedback magnetic fields Hf1 and Hf2 to be kept low.

Further, in the present example embodiment, a parallel connection isformed in some sections of the helical coil 6. In a specific butnon-limiting example, the upper wiring line 6UA may be configured by thefour upper wiring line patterns 61UA to 64UA coupled to each other inparallel, and the lower wiring line 6LA may be configured by the eightlower wiring line patterns 61LA to 68LA coupled to each other inparallel. Accordingly, as compared with a case of using a helical coilthat includes no such parallel connection, the present exampleembodiment makes it possible to arrange a larger number ofmagnetoresistive effect films MR1 to MR4 than the number of turns of thehelical coil 6 in the Y-axis direction. This helps to achieve higherintegration.

Further, in some embodiments, the helical coil 6 used may include thecoil part 6A and the coil part 6B wound in opposite directions to eachother as illustrated in FIGS. 5A and 5B and integrated into one. Thismakes it possible to form within a narrower region the plurality ofmagnetoresistive effect elements 11 to 14 including the magnetoresistiveeffect films MR1 to MR4, the magnetoresistive effect films MR1 to MR4including two pairs of magnetoresistive effect films that are oppositeto each other in terms of the setting/resetting direction for themagnetization directions of the respective magnetization free layers.Furthermore, the use of the single helical coil 6 including the integralcoil parts 6A and 6B makes it possible to reduce the number of terminalsfor power feeding, as compared with a case of providing two helicalcoils. This helps to achieve higher integration.

Further, in some embodiments, the setting/resetting direction for themagnetization free layers S13 and S43 of the magnetoresistive effectfilms MR1 and MR4 and the setting/resetting direction for themagnetization free layers S23 and S33 of the magnetoresistive effectfilms MR2 and MR3 may be opposite to each other. By configuring thebridge circuit 7 with the magnetoresistive effect elements that includepairs of magnetoresistive effect films in which the magnetizationdirections of the respective magnetization free layers upon setting orresetting are opposite to each other, it is possible to reduce noiseresulting from an unwanted disturbance magnetic field and reduce errorresulting from stress distortion.

2. Modification Examples

The technology has been described above with reference to the exampleembodiment. However, the technology is not limited thereto, and may bemodified in a variety of ways. For example, in the foregoing exampleembodiment, four magnetoresistive effect elements are used to form afull-bridge circuit. However, in some embodiments of the disclosure, forexample, two magnetoresistive effect elements may be used to form ahalf-bridge circuit. Further, the plurality of magnetoresistive effectfilms may be identical with each other or different from each other inshape and dimensions. The dimensions of components and the layouts ofthe components are merely illustrative, and are not limited thereto.

In the foregoing example embodiment, the current detection apparatusincluding the helical coil 6 whose winding direction reverses at anintermediate point along the coil has been described; however, thetechnology is not limited thereto. In some embodiments of thedisclosure, the current detection apparatus may include a helical coilthat is wound in one direction, like a helical coil 60 illustrated inFIGS. 8 and 9, for example. FIGS. 8 and 9 are enlarged schematicperspective views of a portion of the helical coil 60 as a modificationexample of the helical coil 6, and correspond to FIGS. 5A and 5B,respectively. The helical coil 60 may include a coil part 60A and a coilpart 60B. As illustrated in FIGS. 8 and 9, the coil part 60A may bewound around the magnetoresistive effect elements 11 and 14 in the firstwinding direction CD1 while extending along the X-axis direction, forexample. The coil part 60B may be wound around the magnetoresistiveeffect elements 13 and 12 in the first winding direction CD1 whileextending along the X-axis direction. A first end of the coil part 60Aand a first end of the coil part 60B may be coupled to each other via acoupling part 60J. The terminal T3 may be coupled to the coupling part60J. The terminal T3 may be a frame ground (FG), for example. Theterminal T1 may be coupled to a second end of the coil part 60A, and theterminal T2 may be coupled to a second end of the coil part 60B.

As illustrated in FIG. 8, the helical coil 60 may be configured toreceive supply of the feedback currents If1 and If2 between, forexample, the terminal T1 and the terminal T2 from the power supply. Notethat in FIG. 8, arrows indicate the feedback current If1 flowing fromthe terminal T2 to the terminal T1. The feedback current If2 is to flowin the opposite direction to the direction indicated by the arrows inFIG. 8, thus flowing from the terminal T1 to the terminal T2.

As illustrated in FIG. 9, the helical coil 60 may be configured toreceive supply of the setting current Is and the resetting current Irbetween the terminal T1 and the terminal T3 and between the terminal T2and the terminal T3 from the power supply. Note that in FIG. 9, arrowsindicate the setting current Is flowing from the terminal T3 to theterminal T1 and also from the terminal T3 to the terminal T2. Theresetting current Ir is to flow in the opposite directions to thedirections indicated by the arrows in FIG. 9, thus flowing from theterminal T1 to the terminal T3 and also from the terminal T2 to theterminal T3.

In the present modification example, the setting and resettingoperations may be carried out by alternately applying the settingcurrent Is and the resetting current Ir between the terminal T1 and theterminal T3 and between the terminal T2 and the terminal T3. Further, indetecting the signal currents Im1 and Im2 flowing through the bus 5,supplying the feedback currents If1 and If2 between the terminal T1 andthe terminal T2 makes it possible to measure the signal currents Im1 andIm2.

In the foregoing example embodiment, the current detection apparatusthat detects a change in a signal current flowing through a conductorhas been described; however, uses of the technology are not limitedthereto. The technology is also applicable, for example, to anelectromagnetic compass that detects geomagnetism, like a magnetic fielddetection apparatus 200 according to one example embodiment of thedisclosure illustrated in FIGS. 10A and 10B. The magnetic fielddetection apparatus 200 illustrated in FIGS. 10A and 10B may be atwo-axis magnetic detection compass that is configured to detect achange in a magnetic field in the Y-axis direction and a change in themagnetic field in the Z-axis direction, for example. FIG. 10A is aschematic planar diagram illustrating an overall configuration exampleof the magnetic field detection apparatus 200. FIG. 10B is a circuitdiagram illustrating a circuit configuration example of the magneticfield detection apparatus 200.

As illustrated in FIG. 10A, the magnetic field detection apparatus 200may include two magnetic field detection units AR2 and AR3 on asubstrate 2.

As illustrated in FIG. 10B, in the magnetic field detection apparatus200, a bridge circuit 7L using four magnetoresistive effect elements 21to 24 may be formed in the magnetic field detection unit AR2, and abridge circuit 7R using four magnetoresistive effect elements 31 to 34may be formed in the magnetic field detection unit AR3. It is possiblefor the magnetic field detection apparatus 200 to detect changes in themagnetic field in the Y-axis direction and the Z-axis direction by usingthe two bridge circuits 7L and 7R. The magnetoresistive effect elements21 to 24 and 31 to 34 are configured to detect a change in a signalmagnetic field to be detected. Here, the magnetoresistive effectelements 21, 23, 31, and 33 may each have a resistance value thatdecreases upon application of a signal magnetic field in the +Ydirection or a signal magnetic field in a +Z direction and increasesupon application of a signal magnetic field in the −Y direction or asignal magnetic field in a −Z direction. The magnetoresistive effectelements 22, 24, 32, and 34 may each have a resistance value thatincreases upon application of a signal magnetic field in the +Ydirection or a signal magnetic field in the +Z direction and decreasesupon application of a signal magnetic field in the −Y direction or asignal magnetic field in the −Z direction. Accordingly, in response to achange in the signal magnetic field, the magnetoresistive effectelements 21, 23, 31, and 33 and the magnetoresistive effect elements 22,24, 32, and 34 may output signals that are different in phase by 180°from each other, for example. The signals extracted from the bridgecircuit 7L may flow into a difference detector 8L, and the signalsextracted from the bridge circuit 7R may flow into a difference detector8R. A difference signal SL from the difference detector 8L and adifference signal SR from the difference detector 8R may both flow intothe arithmetic circuit 9.

The magnetic field detection unit AR2 may be substantially the same instructure as the current detection apparatus 100 described in theforegoing example embodiment except that: the bus 5 is not provided;element formation regions YZ1 and YZ4 are provided in place of theelement formation regions X1 to X4; and a helical coil C2 is provided inplace of the helical coil 6. The helical coil C2 may be substantiallythe same in structure as the helical coil 6, and may include coil partsC2A and C2B. The respective upper wiring lines in the coil parts C2A andC2B may each be a parallel connection including, for example, four upperwiring line patterns coupled to each other in parallel, and may beconfigured to allow a setting current IC2 in the +Y direction to flowtherethrough.

The magnetic field detection unit AR3 may be substantially the same instructure as the current detection apparatus 100 described in theforegoing example embodiment except that: the bus 5 is not provided;element formation regions YZ3 and YZ2 are provided in place of theelement formation regions X1 to X4; and a helical coil C3 is provided inplace of the helical coil 6. The helical coil C3 may be substantiallythe same in structure as the helical coil 6, and may include coil partsC3A and C3B. The respective upper wiring lines in the coil parts C3A andC3B may each be a parallel connection including, for example, four upperwiring line patterns coupled to each other in parallel, and may beconfigured to allow a resetting current IC3 in the −Y direction to flowtherethrough.

FIG. 11A is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect elements 21 and 31 formed in the elementformation region YZ1. FIG. 11B illustrates a cross section along lineXIB-XIB in FIG. 11A as viewed in the direction of the arrows. In theelement formation region YZ1, as illustrated in FIG. 11A, inclinedsurfaces 2L and 2R each extending in the V-axis direction may be formedon a surface of the substrate 2. The V-axis direction may form an angleθ2 with respect to the Y-axis direction. The inclined surfaces 2L and 2Rmay both be inclined with respect to the X-Y plane. The inclined surface2L and the inclined surface 2R may also be inclined with respect to eachother. A plurality of magnetoresistive effect films MRL1 and a pluralityof magnetoresistive effect films MRR1 each extending in the V-axisdirection may be formed on the inclined surface 2L and the inclinedsurface 2R, respectively. The plurality of magnetoresistive effect filmsMRL1 may be coupled to each other in series to form the magnetoresistiveeffect element 21. The plurality of magnetoresistive effect films MRR1may be coupled to each other in series to form the magnetoresistiveeffect element 31. Note that FIG. 11A illustrates the plurality ofmagnetoresistive effect films MRL1 forming the magnetoresistive effectelement 21, the plurality of magnetoresistive effect films MRR1 formingthe magnetoresistive effect element 31, and an upper wiring line patternC2UA disposed thereabove, and omits other components.

The V-axis direction may correspond to a specific but non-limitingexample of a “first axis direction” according to one embodiment of thedisclosure. The inclined surface 2L may correspond to a specific butnon-limiting example of a “first surface” according to one embodiment ofthe disclosure. The inclined surface 2R may correspond to a specific butnon-limiting example of a “second surface” according to one embodimentof the disclosure.

FIG. 12 is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect elements 22 and 32 formed in the elementformation region YZ2. In the element formation region YZ2, the inclinedsurfaces 2L and 2R each extending in the V-axis direction may also beformed on the surface of the substrate 2. The V-axis direction may formthe angle θ2 with respect to the Y-axis direction. A plurality ofmagnetoresistive effect films MRL2 and a plurality of magnetoresistiveeffect films MRR2 each extending in the V-axis direction may be formedon the inclined surface 2L and the inclined surface 2R, respectively.The plurality of magnetoresistive effect films MRL2 may be coupled toeach other in series to form the magnetoresistive effect element 22. Theplurality of magnetoresistive effect films MRR2 may be coupled to eachother in series to form the magnetoresistive effect element 32.

FIG. 13 is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect elements 23 and 33 formed in the elementformation region YZ3. In the element formation region YZ3, the inclinedsurfaces 2L and 2R each extending in the V-axis direction may also beformed on the surface of the substrate 2. The V-axis direction may formthe angle θ2 with respect to the Y-axis direction. A plurality ofmagnetoresistive effect films MRL3 and a plurality of magnetoresistiveeffect films MRR3 each extending in the V-axis direction may be formedon the inclined surface 2L and the inclined surface 2R, respectively.The plurality of magnetoresistive effect films MRL3 may be coupled toeach other in series to form the magnetoresistive effect element 23. Theplurality of magnetoresistive effect films MRR3 may be coupled to eachother in series to form the magnetoresistive effect element 33.

FIG. 14 is a planar diagram for explaining a detailed configuration ofthe magnetoresistive effect elements 24 and 34 formed in the elementformation region YZ4. In the element formation region YZ4, the inclinedsurfaces 2L and 2R each extending in the V-axis direction may also beformed on the surface of the substrate 2. The V-axis direction may formthe angle θ2 with respect to the Y-axis direction. A plurality ofmagnetoresistive effect films MRL4 and a plurality of magnetoresistiveeffect films MRR4 each extending in the V-axis direction may be formedon the inclined surface 2L and the inclined surface 2R, respectively.The plurality of magnetoresistive effect films MRL4 may be coupled toeach other in series to form the magnetoresistive effect element 24. Theplurality of magnetoresistive effect films MRR4 may be coupled to eachother in series to form the magnetoresistive effect element 34.

It should be noted that combining the foregoing magnetic field detectionapparatus 200 with a magnetic field detection unit (which will bereferred to as a magnetic field detection unit AR1 for convenience) thatis configured to detect a change in a magnetic field in the X-axisdirection makes it possible to implement a three-axis magnetic fielddetection compass that detects changes in a magnetic field in three-axisdirections. The magnetic field detection unit AR1 herein may be a unitthat is substantially the same in structure as the current detectionapparatus 100 described in the foregoing example embodiment except thatthe bus 5 is not provided.

Furthermore, the technology encompasses any possible combination of someor all of the various embodiments and the modifications described hereinand incorporated herein.

It is possible to achieve at least the following configurations from theforegoing embodiments and modification examples of the disclosure.

(1)

A magnetic field detection apparatus including:

a magnetoresistive effect element including a magnetoresistive effectfilm that extends in a first axis direction; and

a helical coil including a parallel connection that includes a firstpart and a second part each extending in a second axis directioninclined with respect to the first axis direction, the first part andthe second part being adjacent to each other in a third axis directionand coupled to each other in parallel, the third axis direction beingdifferent from both of the first axis direction and the second axisdirection, the helical coil being wound around the magnetoresistiveeffect element while extending along the third axis direction,

the magnetoresistive effect film overlapping both of the first part andthe second part in a fourth axis direction orthogonal to both of thesecond axis direction and the third axis direction,

the helical coil being configured to be supplied with a current andthereby configured to generate an induction magnetic field to be appliedto the magnetoresistive effect film in the third axis direction.

(2)

The magnetic field detection apparatus according to (1), in which

the magnetoresistive effect film includes a first end part, a second endpart, and an intermediate part between the first end part and the secondend part,

the first part overlaps the first end part in the fourth axis direction,and

the second part overlaps the second end part in the fourth axisdirection.

(3)

The magnetic field detection apparatus according to (2), in which anintensity of the induction magnetic field to be applied to the first endpart and an intensity of the induction magnetic field to be applied tothe second end part are higher than an intensity of the inductionmagnetic field to be applied to the intermediate part.

(4)

The magnetic field detection apparatus according to (2) or (3), in which

the first end part and the second end part respectively include a firstend and a second end of the magnetoresistive effect film that areopposite to each other in the first axis direction,

the first part overlaps the first end in the first end part in thefourth axis direction, and

the second part overlaps the second end in the second end part in thefourth axis direction.

(5)

The magnetic field detection apparatus according to any one of (1) to(4), in which

the helical coil further includes:

-   -   a plurality of third parts each extending in the second axis        direction, the third parts being disposed opposite to the first        part, with the magnetoresistive effect element being interposed        between the first part and the third parts in the fourth axis        direction; and    -   a plurality of fourth parts each extending in the second axis        direction, the fourth parts being disposed opposite to the        second part, with the magnetoresistive effect element being        interposed between the second part and the fourth parts in the        fourth axis direction, and    -   the current is configured to flow through each of the first part        and the second part in a first direction along the second axis        direction, and flow through each of the third parts and the        fourth parts in a second direction opposite to the first        direction.        (6)

The magnetic field detection apparatus according to any one of (1) to(5), in which

a plurality of the magnetoresistive effect elements includes a firstmagnetoresistive effect element and a second magnetoresistive effectelement, and

the helical coil includes:

-   -   a first helical coil part that is wound around the first        magnetoresistive effect element in a first winding direction        while extending along the third axis direction; and    -   a second helical coil part that is wound around the second        magnetoresistive effect element in a second winding direction        opposite to the first winding direction while extending along        the third axis direction, the second helical coil part being        coupled to the first helical coil part in series.        (7)

The magnetic field detection apparatus according to any one of (1) to(5), in which

a plurality of the magnetoresistive effect elements includes a firstmagnetoresistive effect element including a first magnetization freelayer, and a second magnetoresistive effect element including a secondmagnetization free layer, and

the helical coil is configured to generate the induction magnetic fieldto cause a magnetization of the first magnetization free layer and amagnetization of the second magnetization free layer to be oriented inopposite directions.

(8)

A magnetic field detection apparatus including:

a first magnetoresistive effect element including a firstmagnetoresistive effect film that extends in a first axis direction;

a second magnetoresistive effect element including a secondmagnetoresistive effect film that extends in the first axis direction;and

a helical coil including a first parallel connection and a secondparallel connection, the first parallel connection including a firstpart and a second part that each extend in a second axis directioninclined with respect to the first axis direction and that are adjacentto each other in a third axis direction and coupled to each other inparallel, the third axis direction being different from both of thefirst axis direction and the second axis direction, the second parallelconnection including a third part and a fourth part that each extend inthe second axis direction and that are adjacent to each other in thethird axis direction and coupled to each other in parallel, the helicalcoil being wound around the first magnetoresistive effect element andthe second magnetoresistive effect element while extending along thethird axis direction,

the first magnetoresistive effect film overlapping both of the firstpart and the second part in a fourth axis direction orthogonal to bothof the second axis direction and the third axis direction,

the second magnetoresistive effect film overlapping both of the thirdpart and the fourth part in the fourth axis direction,

the helical coil being configured to be supplied with a current andthereby configured to generate an induction magnetic field to be appliedto the first and second magnetoresistive effect films in the third axisdirection.

(9)

The magnetic field detection apparatus according to (8), furtherincluding a substrate including a first surface and a second surface,the first surface being parallel to the first axis direction andinclined with respect to the second axis direction and the third axisdirection, the second surface being parallel to the first axis directionand inclined with respect to the first surface, in which

the first magnetoresistive effect film is provided on the first surface,and

the second magnetoresistive effect film is provided on the secondsurface.

(10)

A current detection apparatus including:

a magnetoresistive effect element including a magnetoresistive effectfilm that extends in a first axis direction;

a helical coil including a parallel connection that includes a firstpart and a second part each extending in a second axis directioninclined with respect to the first axis direction, the first part andthe second part being adjacent to each other in a third axis directionand coupled to each other in parallel, the third axis direction beingdifferent from both of the first axis direction and the second axisdirection, the helical coil being wound around the magnetoresistiveeffect element while extending along the third axis direction, thehelical coil being configured to be supplied with a first current andthereby configured to generate a first induction magnetic field to beapplied to the magnetoresistive effect film in the third axis direction;and

a conductor configured to be supplied with a second current and therebyconfigured to generate a second induction magnetic field to be appliedto the magnetoresistive effect element in the third axis direction,

the magnetoresistive effect film overlapping both of the first part andthe second part in a fourth axis direction orthogonal to both of thesecond axis direction and the third axis direction.

(11)

The current detection apparatus according to (10), further including acontroller configured to control a magnitude of the first current togenerate the first induction magnetic field having an intensity thatcancels out the second induction magnetic field.

The magnetic field detection apparatus according to at least oneembodiment of the disclosure provides high detection accuracy whilebeing small in size.

Although the disclosure has been described hereinabove in terms of theexample embodiment and modification examples, it is not limited thereto.It should be appreciated that variations may be made in the describedexample embodiment and modification examples by those skilled in the artwithout departing from the scope of the disclosure as defined by thefollowing claims. The limitations in the claims are to be interpretedbroadly based on the language employed in the claims and not limited toexamples described in this specification or during the prosecution ofthe application, and the examples are to be construed as non-exclusive.The use of the terms first, second, etc. do not denote any order orimportance, but rather the terms first, second, etc. are used todistinguish one element from another. The term “substantially” and itsvariants are defined as being largely but not necessarily wholly what isspecified as understood by one of ordinary skill in the art. The term“disposed on/provided on/formed on” and its variants as used hereinrefer to elements disposed directly in contact with each other orindirectly by having intervening structures therebetween. Moreover, noelement or component in this disclosure is intended to be dedicated tothe public regardless of whether the element or component is explicitlyrecited in the following claims.

What is claimed is:
 1. A magnetic field detection apparatus comprising: a magnetoresistive effect element including a magnetoresistive effect film that extends in a first axis direction; and a helical coil including a parallel connection that includes a first part and a second part each extending in a second axis direction inclined with respect to the first axis direction, the first part and the second part being adjacent to each other in a third axis direction and coupled to each other in parallel, the third axis direction being different from both of the first axis direction and the second axis direction, the helical coil being wound around the magnetoresistive effect element while extending along the third axis direction, the magnetoresistive effect film overlapping both of the first part and the second part in a fourth axis direction orthogonal to both of the second axis direction and the third axis direction, the helical coil being configured to be supplied with a current and thereby configured to generate an induction magnetic field to be applied to the magnetoresistive effect film in the third axis direction.
 2. The magnetic field detection apparatus according to claim 1, wherein the magnetoresistive effect film includes a first end part, a second end part, and an intermediate part between the first end part and the second end part, the first part overlaps the first end part in the fourth axis direction, and the second part overlaps the second end part in the fourth axis direction.
 3. The magnetic field detection apparatus according to claim 2, wherein an intensity of the induction magnetic field to be applied to the first end part and an intensity of the induction magnetic field to be applied to the second end part are higher than an intensity of the induction magnetic field to be applied to the intermediate part.
 4. The magnetic field detection apparatus according to claim 2, wherein the first end part and the second end part respectively include a first end and a second end of the magnetoresistive effect film that are opposite to each other in the first axis direction, the first part overlaps the first end in the first end part in the fourth axis direction, and the second part overlaps the second end in the second end part in the fourth axis direction.
 5. The magnetic field detection apparatus according to claim 1, wherein the helical coil further includes: a plurality of third parts each extending in the second axis direction, the third parts being disposed opposite to the first part, with the magnetoresistive effect element being interposed between the first part and the third parts in the fourth axis direction; and a plurality of fourth parts each extending in the second axis direction, the fourth parts being disposed opposite to the second part, with the magnetoresistive effect element being interposed between the second part and the fourth parts in the fourth axis direction, and the current is configured to flow through each of the first part and the second part in a first direction along the second axis direction, and flow through each of the third parts and the fourth parts in a second direction opposite to the first direction.
 6. The magnetic field detection apparatus according to claim 1, wherein a plurality of the magnetoresistive effect elements includes a first magnetoresistive effect element and a second magnetoresistive effect element, and the helical coil includes: a first helical coil part that is wound around the first magnetoresistive effect element in a first winding direction while extending along the third axis direction; and a second helical coil part that is wound around the second magnetoresistive effect element in a second winding direction opposite to the first winding direction while extending along the third axis direction, the second helical coil part being coupled to the first helical coil part in series.
 7. The magnetic field detection apparatus according to claim 1, wherein a plurality of the magnetoresistive effect elements includes a first magnetoresistive effect element including a first magnetization free layer, and a second magnetoresistive effect element including a second magnetization free layer, and the helical coil is configured to generate the induction magnetic field to cause a magnetization of the first magnetization free layer and a magnetization of the second magnetization free layer to be oriented in opposite directions.
 8. A magnetic field detection apparatus comprising: a first magnetoresistive effect element including a first magnetoresistive effect film that extends in a first axis direction; a second magnetoresistive effect element including a second magnetoresistive effect film that extends in the first axis direction; and a helical coil including a first parallel connection and a second parallel connection, the first parallel connection including a first part and a second part that each extend in a second axis direction inclined with respect to the first axis direction and that are adjacent to each other in a third axis direction and coupled to each other in parallel, the third axis direction being different from both of the first axis direction and the second axis direction, the second parallel connection including a third part and a fourth part that each extend in the second axis direction and that are adjacent to each other in the third axis direction and coupled to each other in parallel, the helical coil being wound around the first magnetoresistive effect element and the second magnetoresistive effect element while extending along the third axis direction, the first magnetoresistive effect film overlapping both of the first part and the second part in a fourth axis direction orthogonal to both of the second axis direction and the third axis direction, the second magnetoresistive effect film overlapping both of the third part and the fourth part in the fourth axis direction, the helical coil being configured to be supplied with a current and thereby configured to generate an induction magnetic field to be applied to the first and second magnetoresistive effect films in the third axis direction.
 9. The magnetic field detection apparatus according to claim 8, further comprising a substrate including a first surface and a second surface, the first surface being parallel to the first axis direction and inclined with respect to the second axis direction and the third axis direction, the second surface being parallel to the first axis direction and inclined with respect to the first surface, wherein the first magnetoresistive effect film is provided on the first surface, and the second magnetoresistive effect film is provided on the second surface.
 10. A current detection apparatus comprising: a magnetoresistive effect element including a magnetoresistive effect film that extends in a first axis direction; a helical coil including a parallel connection that includes a first part and a second part each extending in a second axis direction inclined with respect to the first axis direction, the first part and the second part being adjacent to each other in a third axis direction and coupled to each other in parallel, the third axis direction being different from both of the first axis direction and the second axis direction, the helical coil being wound around the magnetoresistive effect element while extending along the third axis direction, the helical coil being configured to be supplied with a first current and thereby configured to generate a first induction magnetic field to be applied to the magnetoresistive effect film in the third axis direction; and a conductor configured to be supplied with a second current and thereby configured to generate a second induction magnetic field to be applied to the magnetoresistive effect element in the third axis direction, the magnetoresistive effect film overlapping both of the first part and the second part in a fourth axis direction orthogonal to both of the second axis direction and the third axis direction.
 11. The current detection apparatus according to claim 10, further comprising a controller configured to control a magnitude of the first current to generate the first induction magnetic field having an intensity that cancels out the second induction magnetic field. 